Lenses are characterized by their focal length (between the optical center and the film), aperture (ratio between the diameter of the lens and the focal length) and angle of view (width of the captured image).
Graduated scale that controls the diaphragm’s opening; it is measured in f-stops and a high f-stop indicates a small opening.
depth-of-field scale
Scale that shows the zone of sharpest focus around the subject; this is a function of the diaphragm’s opening and the distance between the lens and the subject.
distance scale
Scale that shows the distance between the lens and the subject on which it is focused.
bayonet mount
Device for attaching the lens to the camera body by fitting lugs located on the lens into grooves on the camera and turning.
focus setting ring
Setting ring that sharpens the image of a subject.
lens
Transparent optical disks through which ambient light enters; the disks correct each other to improve the quality of the image.
